From 368bb77ee36d3bdae42cf77e57cfaa2718f383f4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Jeanneret?= <cjeanner@redhat.com>
Date: Wed, 23 Nov 2022 15:11:44 +0100
Subject: [PATCH] Ensure NetworkManager doesn't override /etc/resolv.conf

Until now, whenever NetworkManager gets reloaded/restarted/lease
refresh, it would override the /etc/resolv.conf file with the
nameservers and related it gets from the network.

This patch ensures this won't happen ever again.

Change-Id: I92bc12b8f712e28962d24dd6474cfce22b81222c
---
 .../nodepool-base/finalise.d/89-boot-settings        | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/nodepool/elements/nodepool-base/finalise.d/89-boot-settings b/nodepool/elements/nodepool-base/finalise.d/89-boot-settings
index 62868c717a..2b36d183a8 100755
--- a/nodepool/elements/nodepool-base/finalise.d/89-boot-settings
+++ b/nodepool/elements/nodepool-base/finalise.d/89-boot-settings
@@ -159,6 +159,18 @@ set -e
 echo 'nameserver 127.0.0.1' > /etc/resolv.conf
 
 EOF
+
+# Configure NetworkManager to not manage /etc/resolv.conf
+if [ -d /etc/NetworkManager/conf.d ]; then
+  cat <<EOF |python3
+  import configparser
+  p = configparser.SafeConfigParser()
+  p.set('main', 'rc-manager', 'unmanaged')
+  with open('/etc/NetworkManager/conf.d/rc-manager.conf', 'w') as fh:
+    p.write(fh)
+EOF
+fi
+
 # openSUSE doesn't have an iptables service, so apply the iptables rules at boot
 if [[ "${DISTRO_NAME}" =~ (opensuse) ]] ; then
     cat >>$rclocal <<EOF